simdesign.rcmrf.bnsm.cp02

BNSM CP02 Library

This package provides an alternative concentrated plasticity (CP) modelling strategy within the Building Nonlinear Structural Model (BNSM). It extends the CP01, by adopting energy-based hysteretic plastic hinge models for beams and columns, following the work of Hasanoglu and O’Reilly (2026).

The classes defined here inherit from the abstract modelling interfaces in bnsm.baselib and extend the CP01 implementations where required, providing instantiable component implementations.

Model Characteristics

  • Beam: Concentrated plasticity with end hinges. Plastic hinge moment-rotation behaviour is defined using an energy-based HystereticSM material formulation (Hasanoglu and O’Reilly, 2026), replacing the default CP01 hinge model.

  • Column: Concentrated plasticity with energy-based rotational hinge formulation (Hasanoglu and O’Reilly, 2026). Shear and axial interaction behaviour follow CP01.

  • Joints: Rigid, elastic, or inelastic rotational spring models (identical to the base implementation).

  • Infill: Equivalent diagonal strut macro-model for masonry infills (Identical to CP01).

  • Floor Diaphragm: Rigid diaphragm modelling via retained node constraints (identical to the base implementation).

  • Foundation: Lumped fixed support node (identical to the base implementation).

  • Building: Aggregator class assembling all nonlinear components into a unified OpenSees domain without modification of base behaviour.

References

Hasanoglu, S. and O’Reilly G. J. (2026). A hysteretic energy–based framework for seismic fragility assessment of ductile reinforced concrete frame buildings